This invention relates generally to the field of digital subscriber line (DSL) technology, and more specifically to a system and method for testing digital subscriber lines.
Digital subscriber line (DSL) technology provides high bandwidth data transfer capabilities using the same connections that have traditionally been used for telephone and voice-band modem communication. These connections are the twisted copper wire pairs connected between the telephone central office (CO) and the customer premises which are referred to as the xe2x80x9clocal loopxe2x80x9d. In order to achieve high data transfer rates over the twisted wire pairs, DSL operates at considerably higher frequencies than e traditional voice-band communication. These high frequency signals are more sensitive to the length and quality of the local loop than the voice-band signals (which are typically less than approximately 4 kHz), and therefore more sophisticated methods of provisioning and management are required to successfully implement DSL.
DSL operates over a limited distance, requiring termination equipment in the central office nearest to the subscriber. Therefore, DSL providers must deploy such equipment at each central office from which they want to offer DSL service. In addition, equipment is also typically installed at the customer premises. Due to the expansive network of equipment that is required, the costs of maintenance and repair of this equipment are significant. In addition, competitive local exchange carriers (CLECs) providing DSL service typically rent space in central offices owned by incumbent local exchange carriers (ILECs), and do not have an on-site presence at the central offices. Therefore, avoiding DSL service outages or degradation, as well as the associated labor and travel costs, are critical to the success of local exchange carriers competing for DSL customers.
In accordance with the present invention, a system and method for testing digital subscriber lines is provided that substantially eliminates or reduces disadvantages or problems associated with previously developed systems and methods.
In one embodiment of the present invention, a system for testing a communication path for digital subscriber line (DSL) signals includes a loop management device coupled in the communication path between a DSL access multiplexer (DSLAM) and a DSL modem located at a customer premises. The system also includes a remote test interface coupled in the communication path between the loop management device and the DSL modem. The loop management device and the remote test interface communicate using voice-band signals transmitted over the communication path and collaboratively test the communication path.
Technical advantages of the present invention include providing a system and method that automate the process of managing digital subscriber lines. This automation enables a local exchange carrier to deploy DSL services quickly and to manage these services with greater reliability, more efficiency, and less expense than with existing systems and methods. The present invention also allows remote management of the DSL infrastructure in the local loop using two-way, voice-band communication between equipment located in the central office and equipment located at the customer premises. This remote management capability provides a reliable and efficient method of characterizing the local loop prior to service initiation. It also provides a method of diagnosing problems that are encountered in the local loop after DSL service has been implemented. This remote management may be performed over various types of connections, such as an Ethernet connection, an RS-232 serial port connection, or a modem connection.
The system and method of the present invention also provide protection switching by cross-connecting communication lines from their existing connection with a DSL access multiplexer (DSLAM) in the central office to an alternative connection with the DSLAM. For instance, if a DSL modem card in the DSLAM fails, the present invention is capable of switching the existing connections with the failed modem card to an alternative modem card. This cross-connect capability also provides a method of changing the type of DSL service provided to a customer.